VRay shadows from tree

[Jiri.Matys]

How to achieve shadows like this? This is render from corona (sorry, dont know the author). I tried many different lightings and HDRs and tree models and this seems impossible in vray, but I hope I am wrong. Sometimes I got "something like this" but it was still far away. Shadow from tree is mainly dark splotch more or less blured and thats it. I want to make it more interesting and detailed, but I cant make it something like this Is there any way please? Did any of you guys test that? Thanks.

[squintnic]

whats your lighting and scene set up?

its definately possible, you may need a smaller sun size to get defined shadows, it also matters how far away the tree is from the wall
it could be invisible to camera tree thats closer to the wall as well... we used to do that a lot for stills

HDRI it will depend on the image used and how bright and tight the sun value is

[Jiri.Matys]

Sure, it depend on tree distance and size of sun. But I saw many of images from corona with very different distance of tree and everytime there is very crisp shadows with those circles. I have sun size at 1, its better then biger sizes. Its true that I didnt try lower sizes, I have to try that.
HDR is important. I tried lot of them mainly from HDRhaven which have high EVs which is good. But still no luck with that

[fixeighted]

Can you link some other similar Corona examples?
This test is with a sun. I figured it must be like this due to some image searches such as the pavement image.

[Jiri.Matys]

Second image looks really nice. I have better result with sun too. If I can ask how you do that?

[fixeighted]

Hehe, well thanks but the second image is a photo - I was looking for confirmation of what I thought the effect might be caused by.
So I tried to mimic that anyway; silly not too ...pretty much the same effect...you reckon?
Tree is 7.2m, sun is 11ish intensity and 2.8 size. Cam dof and bokeh, though little to zero difference.....tweaked exp.

[fixeighted]

Your example image is here, with others...really nice work. https://forum.itoosoft.com/image-upl...ouse-in-woods/
Possibly some of the effect could be caustics from the water in front...maybe...maybe not, it's just that the close-up has lots of bokeh from somewhere - but obviously all done in-scene, so no special tricks I'd guess.

[Jiri.Matys]

He he. But new image looks nice too. It looks like you didnt use sky, only sun? What you mean by "sun is 11ish intensity" ?
But those circle looks nice and crisp. Is there something else? Some tweaking somewhere? Btw what tree did you use?
Thank you.

[Jiri.Matys]

Oh, really you change sun size from 1 to 2.8? Never worked for me Hmm, there must be something...

[fixeighted]

Here's the scene if it's of use https://www.dropbox.com/s/siyjg93wer...ADOWS.max?dl=0
Just replace the tree with whatever looks good - I used a random lime but anything should work. Ones in the example are pines so I'll try those tomorrow.

It was trial and error - thank Chaos for IPR
Without it it would be extremely tedious lol
Anyway, just fiddling with the size and intensity, doubling up with an hdr, 2 suns with different states - this is the better of all those options I think.
The size seems pretty sensitive and would be very scene dependent I think...whatever works
Oh, I did boost things a little with lens effects...reduced the threshold quite a bit to accentuate...also a filmic on top to crush some stuff that was annoying.

[fixeighted]

...and interestingly I just found this thread on the corona forum, asking the very same question and using the exact image example I found Small world.
Anyway the explanation of the phenomena is there....small gaps between leaves act as aperture for the sun, hence why it looks like camera bokeh...I like it when my brain works
https://forum.corona-renderer.com/in...?topic=27348.0

[Jiri.Matys]

eh, never saw this on corona forum. I dont look at corona at all. Only images on vwartclub and so on
Yes, it is like camera bokeh. I just love those circles

Sorry, but not sure about "doubling up with an hdr, 2 suns with different states - this is the better of all those options I think". What you mean? You use hdr and suns together?

Anyway I will look at a file, thank you for that.

[fixeighted]

As someone said, it's exactly bokeh but just not from the camera...it's from the sun using the leaves as aperture and the ground etc as film. Cool
Also, one of the forum users suggested that using stencils on the sun can create different shapes, which so far I find hard to control or predict the outcome of - works though and a great idea

What I mean about doubling the sun was an attempt to have both some sharp shadow and some blurred. In the end I did not think it was a viable option.
The stencil idea works with an untiled opacity map on an enormous plane which is infront of the hdr sun, blocking it a bit, at an arbitrary distance.
This has been great fun trying to work out, so thanks for posting it

[Jiri.Matys]

So there is my test. I found out that this effect is more visible only when sun is very strong. This is why you have your sun at 11 intensity. This is probably the reason why I never got that effect.

[fixeighted]

Yeah it does need a strong sun for sure...hdrs work just fine, though some better than others.
That is looking great
Mission accomplished!